December, '10] WEBSTER: INSECTS OF IOWA 503 



the corn remained in the ground for some little time before it germi- 

 nated. 



Sphenophorus parvulus Gyll. During June much complaint was 

 made of injury to young growing corn plants by bill bugs. In one 

 field near Whiting, Monona County, I found practically 100% injury 

 by this insect. The field was in sod the year previous and had been 

 turned under that spring. Out of 100 hills in a row, -counted con- 

 secutively, every hill was more or less injured by the punctures of 

 bill bugs. The species here concerned was Sphenophorus parvulus. 



Aphis setarice Thos. Plum trees over the state were badly infested 

 with this species of aphid this year. Probably the worst infestation 

 noticed was at Ames. Here the insect reached its maximum about 

 the middle of June, when the plant lice were so thickly crowded on 

 young plum growth so as to quite hide the wood. One's clothes would 

 become stained by the aphids while walking down a row of badly 

 infested young trees. Early in July lady beetles, mainly Coccinella 

 9-notata Herbst and Hippodamia convergens Guer., were very abun- 

 dant on the infested trees and by July 29th on some of these trees 

 not an aphid could be found. A part of them, no doubt, had mi- 

 grated to their alternate food plants among the wild grasses, but it 

 was the abundance of the lady beetles that was responsible for the 

 wholesale clearing out of the plant lice. 



Leptinotarsa 10-lineata Say. This year the ever-present Colorado 

 potato-beetle was much more common than usual. Early in the 

 season many potato fields were threatened with a stripping, but the 

 use of Paris green in most cases checked the insects. 



Epitrix cucumeris Harris. Another insect that was very common 

 on potatoes in Iowa this year was the potato flea-beetle. The injury 

 was first noticed about the middle of June. The beetles were found 

 on the vines from that time until fall. Early potatoes were more 

 injured than the late varieties. 



Empoasca malt LeBaron. The apple leaf-hopper also did con- 

 siderable damage this year to potatoes. The attacks of this insect, 

 together with the injury by the Colorado potato-beetle and the long 

 drought, made potatoes a very poor crop in some localities. 



Chaitophorus negundinis Thos. Box elder trees all over the state 

 were attacked by the box elder aphid, which seems to be fairly com- 

 mon in Iowa nearly every year. The plant lice evidently got a start 

 early in the season, when the late frost took all the foliage from the 

 trees, but apparently did not affect the insects. Many trees were 

 not able to put out a full foliage all through the season, due to the 

 attack of this aphid and also to injury by a species of Eriophyes. 



Meliana alhilinea Hlibner. Injury to timothy heads by the wheat- 



